Apparatuses and method using enhanced control channel information for tdd-fdd carrier aggregation

ABSTRACT

Apparatuses and methods for carrier aggregation are generally described herein. An evolved NodeB (eNB) may transmit downlink control information (DCI) on a control channel portion for a primary cell (PCell) downlink (DL) subframe. The DCI can include an offset field indicating an offset, relative to a first secondary cell (SCell) subframe, to identify a second SCell subframe for which the DCI is providing control information. Other apparatuses and methods are also described.

PRIORITY CLAIM

This application claims priority under 35 USC 119(e) to U.S. ProvisionalPatent Application Ser. No. 61/909,938 filed Nov. 27, 2013, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments described herein pertain generally to wirelesscommunications. More particularly, the present disclosure relates tocarrier aggregation, even more particularly for situations in which thecarriers to be aggregated operate using different duplexingtechnologies.

BACKGROUND

Current 3rd Generation Partnership Project (3GPP) long term evolution(LTE) specifications allow operators to provide carrier aggregation (CA)to improve peak data rates. Currently CA support is only availablebetween bands operating using the same duplexing technology, at least inpart due to difficulties in performing with cross-carrier schedulingwhen bands operate using different duplexing technologies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a system in which someembodiments may be implemented.

FIG. 2 illustrates an example scenario for carrier aggregation with atime-division duplex (TDD) primary cell (PCell) and a frequency-divisionduplex (FDD) secondary cell (SCell).

FIG. 3A illustrates cross-carrier scheduling in accordance withavailable systems.

FIG. 3B illustrates cross-carrier scheduling in accordance with someembodiments.

FIG. 4 illustrates components of a physical downlink control channel inaccordance with some embodiments.

FIG. 5 is a flow chart of a method for TDD-FDD carrier aggregation inaccordance with some embodiments.

FIG. 6 is a block diagram of the basic components of a communicationstation in accordance with some embodiments.

FIG. 7 is a block diagram of a machine for executing variousembodiments.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram illustrating a system 100 in which someembodiments may be implemented. The system 100 includes a user equipment(UE) 102, which can communicate wirelessly with a PCell 104 over awireless communication link 108. Communication link 108 includes one ormore communication channels. These channels can include a physicaluplink control channel (PUCCH), a physical uplink shared channel (PUSCH)with downlink control information (DCI) transmitted on the downlink (orDCI not transmitted on the downlink), and any other channel fortransmitting control (e.g. scheduling or power) information or data onthe uplink or downlink. Because system 100 may support carrieraggregation (e.g. may be an LTE-A system) these channels may include oneor more aggregated component carriers.

PCell 104 may be a cell associated with a macro network, such as, butnot limited to, a radio access network or cellular network. For example,in some examples, PCell 104 can include a PCell in LTE-Advancedcommunication environments. In various embodiments, PCell 104 may beassociated with a PCell network entity 106. The PCell network entity 106will be referred to hereinafter as an evolved node B (eNB), however, itwill be understood that a network entity can include one or more of anytype of network module, such as an access point, a macro cell, includinga base station (BS), node B, a relay, a peer-to-peer device, anauthentication, authorization and accounting (AAA) server, a mobileswitching center (MSC), a radio network controller (RNC), etc.Additionally, the network entity associated with PCell 104 maycommunicate with one or more other network entities of wireless and/orcore networks, such as, but not limited to, wide-area networks (WAN),wireless networks (e.g. 802.11 or cellular network), the Public SwitchedTelephone Network (PSTN) network, ad hoc networks, personal areanetworks (e.g. Bluetooth®) or other combinations or permutations ofnetwork protocols and network types. Such network(s) may include asingle local area network (LAN) or wide-area network (WAN), orcombinations of LANs or WANs, such as the Internet.

In a various embodiments, UE 102 may communicate with one or more SCells110 via one or more communication links 112. In some examples, the oneor more SCells 110 may include SCells in LTE-Advanced communicationenvironments. UE 102 may be configured to communicate simultaneouslywith PCell 104 and the one or more SCells 110, for example, via aplurality of antennas of UE 102. Communication link 112 may include oneor more communication channels, which may include a PUCCH, a PUSCH withDCI transmitted on the downlink (or DCI not transmitted on thedownlink), and any other channel for transmitting control (e.g.scheduling or power) information or data on the uplink or downlink.

SCells 110 may be small cells or low power cells, controlled by orotherwise associated with one or more network entities 114 or modules,such as, but not limited to a low-power access point, such as apicocell, femtocell, microcell, WiFi hotspot, etc. However, embodimentsare not limited thereto. For example, the SCell 110 can be co-locatedwith the PCell 104 in the eNB 106. Additionally, similarly to PCell 104,SCells 110 may communicate with one or more other network entities ofwireless and/or core networks.

Additionally, system 100, which may include PCell 104 and one or moreSCells 110, may comprise a Wideband Code Division Multiple Access(W-CDMA) system, and PCell 104 and one or more SCells 110 maycommunicate with one or more UEs 102 according to this standard. Theactual telecommunication standard, network architecture, and/orcommunication standard employed will depend on the specific applicationand the overall design constraints imposed on the system. The variousdevices coupled to the network(s) (e.g. UE 102 and/or network entitiesserving PCell 104 and/or SCells 110) may be coupled to the network(s)via one or more wired or wireless connections.

The system 100 may support both frequency-division duplex (FDD) andtime-division duplex (TDD) duplexing modes. Efficient TDD and FDDspectrum usage through TDD-FDD joint operations becomes more importantin light of ever-increasing throughput and capacity needs. Carrieraggregation (CA) is one concept that can enhance TDD-FDD jointoperations.

Cross-carrier scheduling is an important aspect of CA that helpsoperators achieve better load balancing across multiple carriers as wellas avoid performance degradation due to control channel interference inheterogeneous network (HetNet) deployments. In some available systems,CA for LTE is available only between bands operating using sameduplexing technology, i.e., between multiple FDD bands or betweenmultiple TDD bands. However, the need for TDD-FDD carrier aggregation isincreasing as more eNBs and UEs become capable of supporting both FDDand TDD.

Introducing support for FDD/TDD CA may create issues with controlchannel design, arising primarily from disparate availability ofdownlink (DL) and uplink (UL) subframes over time between a TDDComponent Carrier (CC) and an FDD CC. Embodiments provide a controlchannel design to help overcome these and other issues. Embodimentsdescribed below are described referring to a TDD PCell 104 and an FDDSCell 110, but it will be appreciated that embodiments are not limitedthereto. Furthermore, FDD and TDD cells can be co-located in one networkentity, or FDD and TDD cells can be non-co-located with ideal backhaul,or FDD and TDD cells can be non-co-located with non-ideal backhaul.

FIG. 2 illustrates an example scenario for CA with a TDD PCell 104 andan FDD SCell 110. If cross carrier scheduling is enabled, the UE 102will look for control channel portions, for example the PhysicalDownlink Control Channel (PDCCH) evolved PDCCH (ePDCCH) or other controlchannel, in the TDD PCell 104 only. According to current 3GPP standards,the control channel portion of a DL subframe of PCell 104 can containallocation information relevant to the SCell 110 subframes that coincidewith the current PCell 104 DL subframe, using identification fields suchas a Carrier Indicator Field (CIF) to identify carriers.

As shown in FIG. 2, depending on the DL/UL configuration of the TDDPCell 104, there could be several UL and DL subframes in the FDD SCell110 without any coincident DL subframe in the TDD PCell 104. As aresult, an eNB such as the network entity 106 (FIG. 1) cannot scheduleresources in many FDD subframes because there are fewer DL subframes inthe TDD PCell 104 available to carry the scheduling information. Radioresources in those FDD subframes will thus be wasted.

To address these and other concerns, embodiments provide enhancements tothe control channel design so that a control channel portion (e.g.,PDCCH, ePDCCH, etc.) of a TDD DL subframe can carry schedulinginformation for multiple FDD subframes preceding the next available TDDDL subframe. Embodiments additionally provide radio resource control(RRC) signaling between eNBs and UEs to configure a TDD-FDD CA-capableUE to receive and use cross-carrier and cross-subframe schedulinginformation provided in various embodiments.

FIG. 3A illustrates cross-carrier scheduling in accordance withavailable systems. PDCCH 300 can carry cross-carrier scheduling 302 fora TDD PCell subframe and the PDCCH can additionally carry cross-carrierscheduling 304 for the current FDD SCell 110 subframe 306.

In contrast, in some embodiments, the TDD PCell 104 control channelportion can carry scheduling information for up to the number of FDDsubframes that might occur before the next TDD DL subframe bytransmitting this scheduling information in one or more DCIs, as neededbased on the number of FDD subframes, on a control channel portion for aPCell 104 DL subframe.

FIG. 3B illustrates cross-carrier scheduling in accordance with someembodiments. In accordance with some embodiments, the PDCCH 308 in theTDD PCell 104 can carry cross-carrier resource allocation information304, 310, 312, 314 for more than one consecutive subframe starting fromthe current subframe 316 in the FDD SCell 110. To make this possible, inembodiments, each DCI will include an offset field indicating an offset,relative to a first SCell 110 subframe, to identify the correspondingSCell 110 subframe for which each DCI is providing control information.This control information can include, for example, schedulinginformation described earlier herein with respect to CA. In someembodiments, the offset field can take the form of an Offset IndicatorField (OIF) as described below with respect to Table 1, althoughembodiments are not limited thereto.

FIG. 4 illustrates components of a PDCCH in accordance with someembodiments. As shown in FIG. 4, the PDCCH will include at least oneDCI. While one DCI is shown, embodiments are not limited to anyparticular number of DCIs.

The DCI includes a CIF, an OIF, and other DCI fields. The number of bitsto be included in the OIF will be based on the maximum ratio of UL to DLsubframes in the TDD PCell 104. Depending on the possible DL/ULconfigurations, there could be maximum of a certain number of ULsubframes between a DL or special (S) subframe before the next DLsubframe in the TDD PCell 104, and accordingly there can be a maximumratio of UL to DL subframes in the TDD PCell 104. In accordance withcurrent 3GPP standards, there will be a maximum number of three such ULsubframes between DL subframes, and accordingly the PDCCH will carry upto four DCIs, one for SCell subframe coincident with the current PCellsubframe and a maximum of three DCIs for SCell subframes coincident withsubframes between the current subframe and the next DL subframe in theTDD PCell 104. The number of bits used for the OIF proposed for variousembodiments is thus two bits long to hold values in the range of 0 to 3,based on the above-described maximum ratio of UL to DL subframes,wherein the OIF indicates a subframe offset with the current subframebeing offset 0. For example, a DCI with OIF set to “01” may convey thescheduling information for the associated UE for the next DL subframe inthe FDD SCell 110. However, embodiments are not limited to anyparticular range or to any particular length of the OIF.

As shown in FIG. 4, the DCI will also include a CIF preceding the OIF toidentify the carrier corresponding to the DCI. This allows the PDCCH toconvey scheduling information for subframes of several carriers.

The eNB 106 will transmit a configuration message to the UE 102 prior totransmitting DCIs. The configuration message can be a message otherwiseinvolved with configuring CA for UEs, although embodiments are notlimited thereto. The configuration message will include an indicatorindicating that the control channel portion of PCell 104 DL subframes iscapable of including control information for more than one SCell 110subframe. The configuration message can be included as part of RRCsignaling in accordance with a standard of the 3GPP family of standards,although embodiments are not limited thereto. The configuration messagenotifies the UE 102 that DCIs transmitted in the control channel portionof subsequent PCell DL subframes will include the offset field (e.g.,OIF) described earlier herein.

The indicator can be included as a field of a cross-carrier schedulingconfiguration information element (IE) within the configuration message.An example cross-carrier scheduling configuration IE containing such anindicator is shown in Table 1. However, it will be understood that Table1 is just an example and other IEs with other fields can be used, orfields can have other names than those shown in Table 1.

TABLE 1 cross carrier scheduling configuration information elements.CrossCarrierSchedulingConfig-r10 ::= SEQUENCE {   schedulingCellInfo-r10 CHOICE {     own-r10 SEQUENCE {-- No crosscarrier scheduling        cif-Presence-r10 BOOLEAN       oif-Presence-rxx BOOLEAN     },    other-r10 SEQUENCE {-- Crosscarrier scheduling     schedulingCellId-r10 ServCellIndex-r10,    pdsch-Start-r10 INTEGER (1..4)     }    } }

Upon receiving an IE in an RRC message including the indicator (e.g.,the oif-Presence-rxx field), the UE 102 will thereby be notified thatthe UE 102 should expect, and parse, OIFs in any received DCIs in orderto access control information for corresponding subframes. The presenceor absence of the OIF field in DCIs will be semi-static, meaning thatany UE 102 configured with the above-described RRC message will continueto look for the OIF in all control channel portions received in theconfigured serving cell (e.g., PCell 104) until the eNB 106 or other eNBtransmits another RRC message to indicate otherwise. Additionally, theeNB 106 will only include the OIF fields in control channel portionsintended for the UEs configured to receive it, to help ensure backwardcompatibility for legacy UEs that do not employ the proposed solution.At a later point, the eNB 106 may to transmit a reconfiguration message,to indicate that the eNB 106 will subsequently refrain from transmittingcontrol information for more than one SCell subframe within a singlePCell DL subframe control channel portion.

FIG. 5 is a flow chart of a method 500 for TDD-FDD carrier aggregationin accordance with some embodiments. The example method 500 is describedwith respect to elements of FIG. 1-4. The eNB 106 can perform at leastsome operations of the method 500.

In operation 502, the eNB 106 transmits DCI on a control channel portion308 (FIG. 3B) for a single PCell DL subframe. Each DCI includes anoffset field as described earlier herein with respect to FIG. 3B toindicate an offset, relative to a first SCell subframe, to identify anSCell subframe for which each corresponding DCI is providing controlinformation.

In operation 504, the eNB 106 transmits a configuration message to UE102, the message including an indicator to notify the UE 102 that the UE102 is to parse the offset field of each DCI. As described earlierherein, the eNB 106 will transmit the configuration message prior totransmitting the DCI. The eNB 106 may subsequently transmit areconfiguration message, to indicate that control information will nolonger be transmitted for more than one SCell 110 subframe within asingle PCell 104 control channel portion.

FIG. 6 is a block diagram of the basic components of a communicationstation 600 in accordance with some embodiments. The communicationstation 600 may be suitable as a UE 102 (FIG. 1) or as an eNB 106 ornetwork entity 114 (FIG. 1). The communication station 600 may supportmethods for carrier aggregation, in accordance with embodimentsdescribed above with respect to FIG. 1-5. It should be noted that whenthe communication station 600 acts as an eNB 106 or network entity 114,the communication station 600 may be stationary and non-mobile.

In some embodiments, the communication station 600 may include one ormore processors and may be configured with instructions stored on acomputer-readable storage device. When the communication station 600serves as a UE 102 (FIG. 2), the instructions may cause thecommunication station 600 to receive a configuration message includingan indicator to indicate that control channel portions of at least somePCell DL subframes shall include control information for more than oneSCell subframe. As described earlier herein, the indicator instructs thecommunication station 600 to parse an offset field of downlink controlinformation (DCI) transmitted by the PCell. The offset field indicatesan offset, relative to a first SCell subframe, to identify a secondSCell subframe for which the corresponding DCI is providing controlinformation.

When the communication station 600 serves as an eNB 106 (FIG. 1), theinstructions will cause the communication station 600 to transmit DCI asdescribed earlier herein with respect to FIGS. 1-5 on a control channelportion for a PCell DL subframe, for one or more SCell subframes. Thecommunication station 600 will also transmit a configuration message,such as the RRC messages described earlier herein, including anindicator to indicate that the control channel portion of PCell DLsubframes are capable of including control information for more than oneSCell subframe.

The communication station 600 may include physical layer circuitry 602having a transceiver 610 for transmitting and receiving signals to andfrom other communication stations using one or more antennas 601. Thephysical layer circuitry 602 may also comprise medium access control(MAC) circuitry 604 for controlling access to the wireless medium. Thecommunication station 600 may also include processing circuitry 606 andmemory 608 arranged to perform the operations described herein. In someembodiments, the physical layer circuitry 602 and the processingcircuitry 606 may be configured to perform operations detailed in FIGS.1-5.

In accordance with some embodiments, the MAC circuitry 604 may bearranged to contend for a wireless medium and configure frames orpackets for communicating over the wireless medium and the physicallayer circuitry 602 may be arranged to transmit and receive signals. Thephysical layer circuitry 602 may include circuitry formodulation/demodulation, upconversion/downconversion, filtering,amplification, etc.

In some embodiments, the processing circuitry 606 of the communicationstation 600 may include one or more processors. In some embodiments, twoor more antennas 601 may be coupled to the physical layer circuitry 602arranged for transmitting and receiving signals. The memory 608 maystore information for configuring the processing circuitry 606 toperform operations for configuring and transmitting message frames andperforming the various operations described herein. The memory 608 maycomprise any type of memory, including non-transitory memory, forstoring information in a form readable by a machine (e.g., a computer).For example, the memory 608 may comprise a computer-readable storagedevice, read-only memory (ROM), random-access memory (RAM), magneticdisk storage media, optical storage media, flash-memory devices andother storage devices and media.

The antennas 601 may comprise one or more directional or omnidirectionalantennas, including, for example, dipole antennas, monopole antennas,patch antennas, loop antennas, microstrip antennas or other types ofantennas suitable for transmission of RF signals. In some embodiments,instead of two or more antennas, a single antenna with multipleapertures may be used. In these embodiments, each aperture may beconsidered a separate antenna. In some multiple-input multiple-output(MIMO) embodiments, the antennas may be effectively separated forspatial diversity and the different channel characteristics that mayresult between each of the antennas and the antennas of a transmittingstation.

In some embodiments, the communication station 600 may include one ormore of a keyboard, a display, a non-volatile memory port, multipleantennas, a graphics processor, an application processor, speakers, andother mobile device elements. The display may be an LCD screen includinga touch screen.

In some embodiments, the communication station 600 may be part of aportable wireless communication device, such as a personal digitalassistant (PDA), a laptop or portable computer with wirelesscommunication capability, a web tablet, a wireless telephone, asmartphone, a wireless headset, a pager, an instant messaging device, adigital camera, an access point, a television, a medical device (e.g., aheart rate monitor, a blood pressure monitor, etc.), or another devicethat may receive and/or transmit information wirelessly.

Although the communication station 600 is illustrated as having severalseparate functional elements, two or more of the functional elements maybe combined and may be implemented by combinations ofsoftware-configured elements, such as processing elements includingdigital signal processors (DSPs), and/or other hardware elements. Forexample, some elements may comprise one or more microprocessors, DSPs,field-programmable gate arrays (FPGAs), application specific integratedcircuits (ASICs), radio-frequency integrated circuits (RFICs) andcombinations of various hardware and logic circuitry for performing atleast the functions described herein. In some embodiments, thefunctional elements of the communication station 600 may refer to one ormore processes operating on one or more processing elements.

Embodiments may be implemented in one or a combination of hardware,firmware and software. Embodiments may also be implemented asinstructions stored on a computer-readable storage device, which may beread and executed by at least one processor to perform the operationsdescribed herein. A computer-readable storage device may include anynon-transitory memory mechanism for storing information in a formreadable by a machine (e.g., a computer). For example, acomputer-readable storage device may include read-only memory (ROM),random-access memory (RAM), magnetic disk storage media, optical storagemedia, flash-memory devices, and other storage devices and media.

FIG. 7 is a block diagram of a machine 700 for executing variousembodiments. In alternative embodiments, the machine 700 may operate asa standalone device or may be connected (e.g., networked) to othermachines.

The machine (e.g., computer system) 700 may include a hardware processor702 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 704 and a static memory 706, some or all of which may communicatewith each other via an interlink (e.g., bus) 708. The machine 700 mayfurther include a power management device 732, a graphics display device710, an alphanumeric input device 712 (e.g., a keyboard), and a userinterface (UI) navigation device 714 (e.g., a mouse). In an example, thegraphics display device 710, alphanumeric input device 712 and UInavigation device 714 may be a touch screen display. The machine 700 mayadditionally include a storage device 716 (i.e., drive unit), a signalgeneration device 718 (e.g., a speaker), a network interfacedevice/transceiver 720 coupled to antenna(s) 730, and one or moresensors 728, such as a global positioning system (GPS) sensor, compass,accelerometer, or other sensor. The machine 700 may include an outputcontroller 734, such as a serial (e.g., universal serial bus (USB),parallel, or other wired or wireless (e.g., infrared (IR), near fieldcommunication (NFC), etc.) connection to communicate with or control oneor more peripheral devices (e.g., a printer, card reader, etc.)

The storage device 716 may include a machine readable medium 722 onwhich is stored one or more sets of data structures or instructions 724(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 724 may alsoreside, completely or at least partially, within the main memory 704,within the static memory 706, or within the hardware processor 702during execution thereof by the machine 700. In an example, one or anycombination of the hardware processor 702, the main memory 704, thestatic memory 706, or the storage device 716 may constitute machinereadable media.

While the machine readable medium 722 is illustrated as a single medium,the term “machine readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 724.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions 724 for executionby the machine 700 and that cause the machine 700 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withinstructions 724. Non-limiting machine readable medium examples mayinclude solid-state memories, and optical and magnetic media. In anexample, a massed machine readable medium comprises a machine readablemedium with a plurality of particles having resting mass. Specificexamples of massed machine readable media may include: non-volatilememory, such as semiconductor memory devices (e.g., ElectricallyProgrammable Read-Only Memory (EPROM), or Electrically ErasableProgrammable Read-Only Memory (EEPROM)) and flash memory devices;magnetic disks, such as internal hard disks and removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 724 may further be transmitted or received over acommunications network 726 using a transmission medium via the networkinterface device/transceiver 720 utilizing any one of a number oftransfer protocols (e.g., frame relay, internet protocol (IP),transmission control protocol (TCP), user datagram protocol (UDP),hypertext transfer protocol (HTTP), etc.).

Although the present inventive subject matter has been described inconnection with some embodiments, it is not intended to be limited tothe specific form set forth herein. One of ordinary skill in the artwould recognize that various features of the described embodiments maybe combined in accordance with the disclosure. Moreover, it will beappreciated that various modifications and alterations may be made bythose of ordinary skill in the art without departing from the scope ofthe disclosure.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. An evolved Node B (eNB) for performing carrieraggregation, the eNB comprising hardware processing circuitry to:transmit downlink control information (DCI) on a control channel portionfor a primary cell (PCell) downlink (DL) subframe, the DCI including anoffset field indicating an offset, relative to a first secondary cell(SCell) subframe, to identify a second SCell subframe for which the DCIis providing control information.
 2. The eNB of claim 1, wherein theoffset field includes a number of bits based on a ratio of DL subframesto uplink (UL) subframes in the PCell, the ratio being configured inaccordance with a standard of the 3rd Generation Partnership Project(3GPP) Long Term Evolution (LTE) family of standards.
 3. The eNB ofclaim 2, wherein the offset has a value ranging from 0 to 3 subframes.4. The eNB of claim 1, wherein the hardware processing circuitry isfurther configured to: transmit a configuration message to a userequipment (UE) prior to transmitting the DCI, the configuration messageincluding an indicator to indicate that the control channel portion ofPCell DL subframes are capable of including control information for morethan one SCell subframe.
 5. The eNB of claim 4, wherein theconfiguration message notifies the UE that DCI transmitted in thecontrol channel portion of subsequent PCell DL subframes will includethe offset field.
 6. The eNB of claim 5, wherein the indicator isincluded as a field of a cross-carrier scheduling configurationinformation element (IE).
 7. The eNB of claim 6, wherein theconfiguration message is transmitted using radio resource control (RRC)messaging in accordance with a standard of the 3GPP family of standards.8. The eNB of claim 4, wherein the hardware processing circuitry isfurther configured to transmit a reconfiguration message, subsequent totransmitting the configuration message, to indicate that the eNB willsubsequently refrain from transmitting control information for more thanone SCell subframe within a single PCell DL subframe control channelportion.
 9. The eNB of claim 1, wherein the PCell and the SCell areco-located.
 10. The eNB of claim 1, wherein the PCell and the SCell arenon-co-located with ideal backhaul.
 11. The eNB of claim 1, wherein thePCell operates using time-division duplex (TDD) technology and the SCelloperates using frequency-division duplex (FDD) technology.
 12. A userequipment (UE) configured for carrier aggregation, the UE comprisingphysical layer circuitry to: receive a configuration message includingan indicator to indicate that control channel portions of at least someprimary cell (PCell) downlink (DL) subframes shall include controlinformation for more than one SCell subframe, wherein the indicatorinstructs the UE to parse an offset field of downlink controlinformation (DCI) transmitted by the PCell, the offset field indicatingan offset, relative to a first secondary cell (SCell) subframe, toidentify a second SCell subframe for which the corresponding DCI isproviding control information.
 13. The UE of claim 12, wherein theoffset field includes a number of bits based on a maximum ratio of DLsubframes to uplink (UL) subframes in the PCell, the maximum ratio beingconfigured in accordance with a standard of the 3rd GenerationPartnership Project (3GPP) Long-Term Evolution (LTE) family ofstandards.
 14. The UE of claim 12, wherein the physical layer circuitryis further configured to: receive a plurality of sets of DCI on acontrol channel portion of a single PCell DL subframe; and parse offsetfields from each DCI of the plurality to access corresponding controlinformation for a plurality of SCell subframes.
 15. The UE of claim 12,wherein the indicator is included as a field of a cross-carrierscheduling configuration information element (IE) and wherein theconfiguration message is received in a radio resource control (RRC)messaging.
 16. A non-transitory computer-readable medium that storesinstructions for execution by one or more processors to cause a machineto perform carrier aggregation operations including: operating atime-division duplex (TDD) primary cell (PCell) and a frequency divisionduplex (FDD) secondary cell (SCell); transmitting a plurality ofdownlink control information (DCI) on a control channel portion for aPCell DL subframe, each DCI of the plurality including an offset fieldindicating an offset, relative to a first SCell subframe, to identify asecond SCell subframe for which the corresponding DCI is providingcontrol information, the offset field including a number of bits basedon a maximum ratio of DL subframes to uplink (UL) subframes in thePCell, the maximum ratio being configured in accordance with a standardof the 3rd Generation Partnership Project (3GPP) Long-Term Evolution(LTE) family of standards.
 17. The non-transitory computer-readablemedium of claim 16, wherein the operations further comprise:transmitting a configuration message to a user equipment (UE) prior totransmitting the DCI, the configuration message including a field of across-carrier scheduling configuration information element (IE)indicating that a control channel portion of a PCell downlink (DL)subframe is configured to include control information for more than oneSCell subframe.
 18. The non-transitory computer-readable medium of claim16, wherein the configuration message is transmitted using radioresource control (RRC) messaging in accordance with a standard of the3GPP family of standards.
 19. A method for carrier aggregation, themethod comprising: transmitting a plurality of downlink controlinformation (DCI) on a control channel portion for a single primary cell(PCell) downlink (DL) subframe, each DCI including an offset fieldindicating an offset, relative to a first secondary cell (SCell)subframe, to identify an SCell subframe for which each corresponding DCIis providing control information; and transmitting a configurationmessage to a user equipment (UE) prior to transmitting the plurality ofDCI, the configuration message including an indicator to notify the UEthat the UE is to parse the offset field of each DCI.
 20. The method ofclaim 19, wherein the offset field includes a number of bits based on amaximum ratio of DL subframes to uplink (UL) subframes in the PCell, themaximum ratio being configured in accordance with a standard of the 3rdGeneration Partnership Project (3GPP) Long-Term Evolution (LTE) familyof standards.
 21. The method of claim 19, further comprising:transmitting a reconfiguration message, subsequent to transmitting theconfiguration message, to indicate that control information will nolonger be transmitted for more than one SCell subframe within a singlePCell control channel portion.
 22. The method of claim 19, furthercomprising: operating the PCell using time-division duplex (TDD)technology; and operating the SCell using and a frequency-divisionduplex (FDD) technology.